Dry-type transformer coil windings are typically cast using inner and outer metal casting molds that surround the inner and outer surfaces of the transformer coil windings. The end surfaces of the casting molds may be open and therefore used to introduce an insulating material such as a polymeric or an epoxy material, depending on the casting process utilized. In a transformer having a linear core wherein the legs of the core are arranged in an “E” formation, inner and outer molds work well because the coils can be wound and cast apart from the core. The molds are then removed and the finished coils are mounted to the core legs, respectively.
However, in a dry-type transformer that has a non-linear or triangular core, the core frames that comprise the core are closed. A closed core requires that the coils are wound directly onto the core. The closed core presents difficulty in maneuvering and removing the metal molds from the newly cast coils. As metal can cause degradation of the insulating material on the coils, the molds must be removed from the coils after casting. Thus, the metal molds must often be pried off of the newly cast coils. In removing the molds from the coils, damage may occur to the coils and insulating material. Therefore, there is a need for improvement in coil casting methods for non-linear transformers.